Improved adjustment means for distributor contacts and bearings

ABSTRACT

A distributor for internal combustion. The distributor has a rotary cam provided with a number of lobes, and these lobes are respectively provided with marks which precisely indicate the crests of the lobes. A breaker plate surrounds the cam and carries a swingable contact arm one end of which is successively engaged by the cam lobes. This end of the contact arm and the breaker plate are respectively provided with marks which when respectively aligned with a pair of the marks of a pair of cam lobes indicate that the points are set at their widest gap, so that it then becomes possible to adjust the gap between the points.

United States Patent [45] Patented Mar. 2, 1971 [54] IMPROVED ADJUSTMENTMEANS FOR DISTRIBUTOR CONTACTS AND BEARINGS 9 Claims, 1 Drawing Fig.

[52] US. Cl 200/19, 200/22, 200/25, 200/29, 200/31, 200/153, 74/568 [51]Int. Cl 1101b 19/00, 1-10lh 19/62 [50] Field of Search 200/19- [5 6]References Cited UNITED STATES PATENTS 2,923,785 2/ 1960 Longenecker200/31 3,196,224 7/1965 Tagliabue ZOO/22 FORElGN PATENTS 1,185,1232/1959 France 200/31 Primary Examiner-Robert K. Schaefer AssistantExaminer-J. R. Scott Att0rneyBlum, Moscovitz, Friedman and KaplanABSTRACT: A distributor for internal combustion. The distributor has arotary cam provided with a number of lobes, and these lobes arerespectively provided with marks which precisely indicate the crests ofthe lobes. A breaker plate surrounds the cam and carries a swingablecontact arm one end of which is successively engaged by the cam lobes.This end of the contact arm and the breaker plate are respectivelyprovided with marks which when respectively aligned with a pair of themarks of a pair of cam lobes indicate that the points are set at theirwidest gap, so that it then becomes possible to adjust the gap betweenthe points.

IMPROVED ADJUSTMENT MEANS FOR DISTRIBUTOR CONTACTS AND BEARINGSBACKGROUND OF THE INVENTION The present invention relates todistributors used in internal combustion engines for distributing thespark in a given sequence among the cylinders of the engine.

As is well known it is necessary from time to time to adjust suchdistributors so that the breaker points thereof will have a given gaptherebetween. In order to adjust the gap between the breaker points ofsuch distributors, so as to achieve an accurate setting of these points,the points are first situated at a location providing the maximum orwidest gap therebetween. Once this latter position is reached, it ispossible to proceed in a very accurate manner to provide the desiredsetting of the gap between the points.

One of the difficulties encountered with conventional distributorsresides in the fact that it is extremely difficult to determine when thepoints are set at their widest gap. If the distributor remains connectedwith the engine, it is necessary to determine this maximum gap settingby eye, and the inherent inaccuracies in such procedures-result inundesirably poor settings of the breaker points It has therefore becomecustomary in the practice to remove the distributor from the engine andto utilize relatively expensive testing and tuning equipment in order toachieve an accurate setting for the breaker points. However, unless thevehicle which has the distributor is located at a shop which issufficiently large and well equipped to be provided with suchtesting andtuning equipment, equipment of this latter type simply is not availableand the result is poor settings of the breaker points because of theunavoidable inherent inaccuracies, as set forth above.

In addition, in order to provide a smooth accurate operation for thedistributor it is essential that the camshaft which carries thedistributor cam rotate in good bearings so that an accurate rotarymovement of the cam about its axis can be assured. After operation of adistributor over a given period of time the bearings of the camshaftbecome worn with the result that the accuracy of the operation of thedistributor suffers. When the play of the shaft in the bearings becomessufficiently great it is necessary to recondition the distributor inorder to again achieve the best possible operation. However, at thepresent time it is difficult to determine when the reconditioning isnecessary. In this case also it is'only by eye or by a sense of feelthat a mechanic will judge the necessity of reconditioning thedistributor because the bearing play is too great, and with these latterprocedures there are unavoidable inaccuracies resulting either inreconditioning of distributors which do not require reconditioning or inlack of reconditioning where such reconditioning is indeed required.

SUMMARY OF THE INVENTION It is accordingly a primary object of thepresent invention to provide a distributor structure which will avoidall the above drawbacks.

In particular, it is an object of the invention to provide a distributorwith a structure which will very readily indicate when the breakerpoints are at their widest gap, without requiring the distributor to beremoved from the engine.

In addition, it is an object of the invention to provide a structurewhich can accomplish this result while increasing the cost of thedistributor to a minimal extent.

Furthermore, it is an object of the invention to provide fordistributors various color codes for indicating markings so that thesettings can be made for distributors to be used with engines havingdifferent numbers of cylinders.

Furthermore, it is an object of the invention to provide a constructionof the above general type which will indicate precisely the extent ofwear of the bearings, so that an accurate indication of the necessityfor reconditioning can be achieved.

With the structure of the invention a rotary cam of the distributor isprovided with visible marks which respectively coincide with the crestsof the cam lobes. A breaker plate surrounds the cam and the platecarries a swingable contact arm which has an end which is successivelyengaged by cam lobes during rotary movement of the cam, as is wellknown. This end cf the contact arm and the breaker plate itself arerespectively provided with a pair of marks which when respectivelyaligned with a pair of marks of a pair of the cam lobes accuratelyposition the distributor in a condition where the points thereof are attheir maximum distance from each other. In this way it becomes possibleto achieve very accurately, without removing the distributor from theengine, an initial position where the widest gap between the pointsprevails, so that thereafter it is a simple matter to achieve therequired accurate setting of the gap between the points.

BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated by way ofexample in the accompanying drawing which forms part of this applicationand in which a distributor is shown in a top plan view provided with thestructure of the invention, the cover being removed from the distributorhousing so as to clearly illustrate the structure therein. I

Referring to the drawing, the entire distributor l0 illustrated thereinis conventional except for the indicator markings and graduations asreferred to below. Thus with the present invention it is only requiredto alter a conventional distributor by providing it with suitableindicator marks, so that the cost involved in providing a distributor inaccordance with the present invention is hardly more than the cost of aconventional distributor.

The distributor 10 has a conventional housing 12 which at its bottomwall 14 supports, in a known way, a shaft 16 for rotary movement withina suitable'unillustrated bearing. This shaft 16 carries a cam 18 whichrotates with the shaft, and this cam has a series of cam lobes 20, as iswell known. The cam 18 carries a plurality of marks 22 of the invention,and these marks are in the form of relatively short lines extendingradially from the axis of the shaft 16 and respectively coinciding withthe crests 24 of the cam lobes.

The housing 12 carries in its interior, in a well-known manner, abreaker plate 26 formed with a central opening 28 in which the cam 18 isaccommodated. Thus, the plate 26 surrounds the cam 18. This plate 26carries, as is also conventional, a spring-pressed swingable contact arm30. This arm 30 has an end 32 also of conventional construction which issuccessively engaged by the lobes 20 as the cam 18 rotates with theshaft 16. In this way during the oscillatory swinging of the arm 30 thepoints 34a and 34b will be moved into and out of engagement with eachother in a well-known manner so as to make and break the electricalcircuit which provides the energy for the actuation of the spark plugsto achieve sparks in the cylinders in a given sequence.

In accordance with the invention the end 32 of the contact arm 30 isprovided with a mark 36 and the breaker plate 26 is itself provided witha mark 38 angularly displaced through with respect to the mark 36 aboutthe axis of the camshaft. With this construction when one of the marks22 on the cam '18 is aligned with the mark 36 on another of the marks 22is aligned with mark 38, the points 34a and 34b are at their maximumfrom each other, thus achieving a maximum gap between these points. Oncethis latter condition is accurately achieved it is a simple matter toprovide an accurate setting of the gap between the points in awell-known manner. Thus it becomes possible with this construction toprovide the widest gap between the breaker points in an exceedinglysimple and highly accurate manner without removing the distributor fromthe engine.

v The marks 22 on the cam can be provided in accordance with a givencolor code. Thus one set of marks of a given color can be displaced by90 with respect to each other about the camshaft axis for 4-cylinderengine. A different color can be used for marks displaced by 60 withrespect to each other about the camshaft axis for 6-cylinder engines. Inthe case of 8-cylinder engines, a still further distinctive color can beused for a set of marks which will be displaced from each other by 45about the camshaft axis. Of course, in all of these cases the enginesare 4-cycle engines. However, similar angles can be used for 2-cycleengines since the marks scribed on the cam can be placed where the camwill open the breaker points to their widest gap.

It is also possible with the structure as shown in the drawing todetermine the extent of bearing wear. Thus, with the parts in theposition shown in the drawing, the operator need only push the shaft 16toward the arm 30, or-more precisely the end 32 thereof and the mark 36on this end 32. This will result in displacement of that mark 22 whichis aligned the mark 38 laterally with respect to the latter. It can bejudged from the extent of lateral displacement of such a mark withrespect to the mark 38 whether it is necessary to recondition thebearing. In other words the extent of displacement under theseconditions will give an indication of the extent of wear of thebearings. 1

However, in this case also, in order that there be no guesswork in thedetermination of whether or not reconditioning is required, the breakerplate 26 is provided with a plurality of additional graduations 40 oneof which is formed by the mark 38 which is preferably located centrallybetween the end graduations of the series of graduations 40. Thus, it ispossible to determine the number of graduations along which the mark 22which is aligned with the mark 38 is displaced when pushing on thecamshaft 16. In this way'the operator will know, for example, that ifthe extent of displacement is only through a distance of one or twograduations the distributor does not require any reconditioning whereasif the displacement is through three or more graduations thenreconditioning is under all circumstances essential.

It is thus apparent that with the simple structure of the invention itbecomes possible on the one hand to very precisely determine the maximumwidth of the gap between the points so that an accurate adjustment ofthe points can be made, and on the other hand the extent of bearing wearcan also be determined so that a decision can be made with respect towhether or not reconditioning of the distributor is required.

lclaim:

1. In a distributor for an internal combustion engine, a rotary camhaving a plurality of lobes, a breaker plate surrounding said cam, and aswingable contact arm carried by said plate and having an endsuccessively engaged by the lobes of said cam during rotary movement ofthe latter, said cam carrying at least two marks visible and alignedwith two lobes of said cam, and said end of said arm and said breakerplate respectively carrying visible marks which when alignedrespectively with said marks of said cam automatically situate breakerpoints of the distributor at their widest gap, so that thereafter thewidth between said points may be adjusted.

2. The combination of claim I and wherein said cam has more than twolobes, and all of the lobes of said cam being respectively provided withmarks so that any selected pair of said marks may be respectivelyaligned with said marks on said arm and plate to determine the widestgap between the breaker points.

3. The combination of claim 2 and wherein the marks on said cam areprovided with a-color code according to which one set of marks of onecolor are angularly displaced with each other by for 4-cylinder engines,another set of marks are of a different color and separated from eachother by 60 for 6-cylinder engines, and a third'set of marks have adistinguishing color and are separated from each other by 45 for 8-cylinder engines, with all of said engines being 4-cycle engmes.

4. The combination of claim 1 and wherein said marks on said end of saidarm and said breaker plate are angularly displaced from each other aboutthe axis of said cam by 90.

5. The combination of claim 4 and wherein said breaker plate carries aseries of graduations one of which coincides with said mark on saidbreaker plate, so that a camshaft which carries said cam, upon beingpushed toward said arm, will displace the mark aligned with said breakerplate mark through a distance indicative of the degree of wear inbearings, so that an indication is provided of a requirement forreconditioning of the distributor.

6. The combination of claim 5 and wherein said mark on said breakerplate is situated midway between the first and last of the series ofgraduations.

7. In a distributor for an internal combustion engine, a rotary camhaving a plurality of lobes, a breaker plate surround ing said rotarycam, at least one mark carried by said cam at one of said lobes thereof,and at least one additional mark carried by said plate to be alignedwith said mark on said cam, whereby when said marks are aligned a shaftwhich carries said cam can be pushed in a direction perpendicular to aradial line extending throughthe axis ofsaid cam and the aligned marks,thus displacing the cam mark with respect to the plate mark to providean indication of the degree of wear of the camshaft bearings, so as toindicate whether or not recondi tioning of the distributor is required.

8. The combination of claim 7 and wherein said breaker plate hasgraduations one of whichcoincides with said mark on said breaker platefor indicating the degree of wear of the bearings.

9. The combination of claim 8 and wherein said graduations are situatedon both sides of the mark of said breaker plate with the lattercentrally located between the ends of the series of graduations.

1. In a distributor for an internal combustion engine, a rotary camhaving a plurality of lobes, a breaker plate surrounding said cam, and aswingable contact arm carried by said plate and Having an endsuccessively engaged by the lobes of said cam during rotary movement ofthe latter, said cam carrying at least two marks visible and alignedwith two lobes of said cam, and said end of said arm and said breakerplate respectively carrying visible marks which when alignedrespectively with said marks of said cam automatically situate breakerpoints of the distributor at their widest gap, so that thereafter thewidth between said points may be adjusted.
 2. The combination of claim 1and wherein said cam has more than two lobes, and all of the lobes ofsaid cam being respectively provided with marks so that any selectedpair of said marks may be respectively aligned with said marks on saidarm and plate to determine the widest gap between the breaker points. 3.The combination of claim 2 and wherein the marks on said cam areprovided with a color code according to which one set of marks of onecolor are angularly displaced with each other by 90* for 4-cylinderengines, another set of marks are of a different color and separatedfrom each other by 60* for 6-cylinder engines, and a third set of markshave a distinguishing color and are separated from each other by 45* for8-cylinder engines, with all of said engines being 4-cycle engines. 4.The combination of claim 1 and wherein said marks on said end of saidarm and said breaker plate are angularly displaced from each other aboutthe axis of said cam by 90*.
 5. The combination of claim 4 and whereinsaid breaker plate carries a series of graduations one of whichcoincides with said mark on said breaker plate, so that a camshaft whichcarries said cam, upon being pushed toward said arm, will displace themark aligned with said breaker plate mark through a distance indicativeof the degree of wear in bearings, so that an indication is provided ofa requirement for reconditioning of the distributor.
 6. The combinationof claim 5 and wherein said mark on said breaker plate is situatedmidway between the first and last of the series of graduations.
 7. In adistributor for an internal combustion engine, a rotary cam having aplurality of lobes, a breaker plate surrounding said rotary cam, atleast one mark carried by said cam at one of said lobes thereof, and atleast one additional mark carried by said plate to be aligned with saidmark on said cam, whereby when said marks are aligned a shaft whichcarries said cam can be pushed in a direction perpendicular to a radialline extending through the axis of said cam and the aligned marks, thusdisplacing the cam mark with respect to the plate mark to provide anindication of the degree of wear of the camshaft bearings, so as toindicate whether or not reconditioning of the distributor is required.8. The combination of claim 7 and wherein said breaker plate hasgraduations one of which coincides with said mark on said breaker platefor indicating the degree of wear of the bearings.
 9. The combination ofclaim 8 and wherein said graduations are situated on both sides of themark of said breaker plate with the latter centrally located between theends of the series of graduations.